Optical emission device

Abstract

An optical emission device with an emitter semiconductor chip and a cover intended to be suitable for backlighting areas, the device having a comparatively low structural height and low packing density. The cover has a light aperture formed using a convex and concave lens for radiating light in a solid angle of maximum size. This device can also be used in combination with an additional external reflector and diffusion screen.

We claim: 
     
       1. An optical emission device for radiating light in a solid angle comprising: an emitter semiconductor chip positioned on an optical axis of the device;   a cover having a light aperture which is composed of a concave lens for radiating light from the emitter semiconductor chip into a solid angle of maximum size, the concave lens intersecting the optical axis, the cover including a convex lens which is positioned around the concave lens, wherein the convex lens contacts the concave lens such that there is a smooth transition region between the lenses, the convex lens surrounding the border of the concave lens for uniformly distributing light into said solid angle of maximum size.   
     
     
       2. The optical emission device of claim 1 wherein the curvature of the concave lens is substantially two times as large as the curvature of the convex lens. 
     
     
       3. The optical emission device of claim 1 further comprising a planar chip carrier for the emitter semiconductor chip. 
     
     
       4. The optical emission device of claim 2 further comprising a planar chip carrier for the emitter semiconductor chip. 
     
     
       5. The optical emission device of claim 1 wherein the emitter semiconductor chip has lambertain characteristics. 
     
     
       6. The optical emission device of claim 1 further comprising an external reflector, the external reflector surrounding the cover for deflecting the radiation emerging under a large angle out of the cover. 
     
     
       7. The optical emission device of claim 3 further comprising an external reflector, the external reflector surrounding the cover for deflecting the radiation emerging under a large angle out of the cover. 
     
     
       8. The optical emission device of claim 6 further comprising a diffusion screen fixed to the reflector, the diffusion screen being fixed to the external reflector in that region where the radiation leaves the reflector to make the radiation of the optical emission device homogeneous. 
     
     
       9. The optical emission device of claim 7 further comprising a diffusion screen fixed to the reflector, the diffusion screen being fixed to the external reflector in that region where the radiation leaves the reflector to make the radiation of the optical emission device homogeneous. 
     
     
       10. The optical emission device of claim 1 constructed as a surface mounted device component. 
     
     
       11. The optical emission device of claim 6 constructed as a surface mounted device component. 
     
     
       12. The optical emission device of claim 8 constructed as a surface mounted device component.